The Microscope. 339 



CRYSTALLINE FORMATIONS OF BUTTER AND OTHER 



FATS. 



BY DR. THOMAS TAYLOR, U. S. AGRICULTURAL DEPARTMENT, 

 WASHINGTON, D. C. 



TT'IGURES 1, 2, 3 and 4. Represent primary ciystals of boiled 

 "^ butter, from milch cows of different breeds under differing 

 conditions of feed. x80 to 110. 



Figures 5 and 0. Represent secondary or rosette crystals 

 forming within the primary or globose crystals. 



Figures 7 and 8. Represent these secondary or rosette crystals 

 having separated from the primaiy crystals. The secondaries gen- 

 erally break up into stellate forms in the process of decay. xSO 

 to 110. 



Figures 9, 10 and 11. Represent tertiary crystals, or the third 

 transition stage of the butter crystal ; generally seen in boiled but- 

 ter that has been kept several months. xSO to 140. 



Figure 12. Represents tertiary crystals resolving into the 

 amorphous condition. xl40. 



Figures 13, 14, 15 and 16. Represent oleomargarine which has 

 no typical form or crystal. xSO to 110. 



Figure 17. Represents oleo as it generally appears when boiled 

 and cooled. xl40. 



Figure 18. Represents neutral lard when boiled and cooled. 

 xl40. 



Figures 19 and 20. Represent common lard when boiled and 

 cooled. xl40 to 400. 



Figures 21, 22, 23 and 24. Represent crystals of beef-fat from 

 various tissues of the ox. Omentum, kidney, marrow of femur and 

 round. x65. 



The crystals are obtained by simply boiling, straining and cool- 

 ing the fat, at a temperature of about 60^^ F., using no chemicals. 



SLIDE-INDEX. 



EUGENE PINCKNEY. 



^~T~^HE catalogues prepared by Ward and others may serve their 

 -^ purpose as a record, but not as an index. Every worker 

 needs a reliable slide-index, to which he may turn for instant 

 reference. I suggest the following : Purchase a six-quire blank 

 book, commonly known as "Record" form, plain blue lines for 



